In recent years, beginning with environmental problems power generation devices with a low environmental burden are being demanded. In addition, together with the development circumstances of electronic paper or bio-electronic devices such as health monitoring which are dominant as a near future device, the demand for next generation power generation devices continues to head towards to conventional safety and light weight as well as clean, flexible and small scale devices. Given these circumstances, since a biofuel cell which generates power using a fuel derived from living matter also includes much appeal (close biofuel (sugars, alcohol), mild operating environment (normal temperature, neutrality, atmosphere), unnecessary fuel refinement and unnecessary separator etc), they are attracting attention worldwide.
A biofuel cell is a type of fuel cell which includes a structure in which an enzyme which oxidizes a fuel derived from living matter is fixed to an anode electrode, an enzyme which reduces an enzyme is fixed to a cathode electrode and electrical energy is obtained from a fuel derived from living matter using an oxidation reduction reaction by these enzymes.
However, there are many problems in the material, components and packaging technology of a biofuel cell derived from a chemical battery or a biosensor. Because an electrode material with carbon as constituent element has excellent safety, durability and biocompatibility, it is used widely in sensors or batteries and is usually attached to carbon fine particles using a binder. For example, a procedure in which low temperature firing carbon fine particles are adsorbed on an electrode and an enzyme is fixed to the inner space or external surface of the fine particles is reported in Japanese Laid Open Patent 2007-34537. However, pore size in which matches the size of a protein can't be controlled and there is no flexibility. In addition, enzyme fixing to a carbon nanotube aggregate orientated in a perpendicular direction on a substrate is previously reported by the inventors in Japanese Laid Open Patent 2009-222459 or in non-Japanese Laid Open Patent 2007-34537, and an enzyme modification to a carbon nano-fiber is reported in non-Japanese Laid Open Patent 2009-222459. However, in each of these reports the carbon nanotube aggregate integrally formed with a support and does not contain flexibility.